Alkylation of isobutane with ethylene and with aluminum halide hydrocarbon complex catalyst using two reactors in series

ABSTRACT

In the production of diisopropyl-containing alkylate by alkylating isobutane with ethylene in the presence of an aluminum halide catalyst wherein ethylene, isobutane and catalyst are charged to a first reactor and the effluent therefrom is charged to a second reactor the components are more severely admixed in the first reactor than in the second reactor to produce an alkylate of maximum octane, to convert a maximum of ethylene feedstock to alkylate and to produce an emulsion from the second reactor that will break.

United States Patent [191 Hutson, Jr. et .al.

ALKYLATlON OF ISOBUTANEWITH Dec. 17, 1974 [54] 2,674,637 4/1954 Marine260/683.53

ETHYLENE AND H ALUh/NUM 3,418,391 12/1968 Cabbage 260/633.57 2.890.2516/1959 Flavinet a1... 260/68353 HALIDE HYDROCARBON COMPLEX 2,354,8518/1944 Danforth 260/683.45 CATALYST USING TWO'REACTORS IN SERIES vFOREIGN PATENTS OR APPLlCATlONS Inventors: T ma so J D a J. CanadaMakovec, both of Bartlesville, Okla.

Primary ExaminerDelbert E. Gantz [73] Asslgnee: Phmlps Petroleum lAssistant Examiner-G. J. CrasanakiS v Bartlesvllle, Okla. 22 FiledzSept. 11, 1972 [571' ABSTRACT [21 Appl. No.: 287,736 In the productionof diisopropyl-containing alkylate by alkylatingisobutane with ethylenein the presence of an aluminum halide catalyst wherein ethylene, isobuE2 5" 3' tame and catalyst are charged to a first reactor and the 58]Fie'ld 68345 effluent therefrom is charged to a second reactor the bcomponents are more severely admixed in the first reactor than in thesecond reactor 'to produce an alkylate of maximum octane, to convert amaximum of [56] References Cited ethylene feedstock 'to alkylate and toproduce an UNITED STATES PATENTS emulsion from the second reactor thatwill break. 2,409,389 10/1946 Ringhamm 260/683.57 2.513.307 8/1950Groebe 260l683.53. 3 Claims, 1 Drawing Flgllre REACTOR 1' REACTOR 11SETTLER 3 I 7 10 I a? :l

5 Q *8 It 1 D ISOBUTANE S v 1 r y a I 2 WF* ETHYLENE S v coMPLEx PUMPALKYLATION OF-ISOISUTANE WITH ETI-IYLENE AND WITH ALUMINUM HALIDEHYDROCARBON COMPLEX CATALYST USING TWO REACTORS IN SERIES BACKGROUND OFTHE INVENTION This invention relates to alkylation reactions. In one ofits aspects, this invention relates to the'alkylation of isobutane andethylene to produce an alkylation product containing diisopropyl. Inanother of its aspects, it relates to the production of alkylateproducts of high research octane number (RON). In still another of itsaspects, it relates to the maintenance of high conversion rates forethylene feedstock into alkylate products.

In one of its concepts this invention relates to the control of reactionconditions of two reactors in series to yield'an alkylate reactionproduct of high RON with minimum sacrifice of conversion of feedstock toalkylate product. r

In a commercial operation for the production of alkylate one of the mostimportant criteria is the production of alkylate product having a highresearch octane number (RON). It has been known that high RON can bemaintained in an alkylate product, but this is usually done atthe-expense of conversion rateof feedstock to alkylate product.Conversely, the maintenance of a high conversion rate of feedstock toalkylate product usually produces, particularly when the alkylatecontains diisopropyl, an. alkylate product with an RON reduced belowthat desired. It has now been discovered that the RON can be held at ahigh level without sacrifice of feedstock conversionby properlymaintaining reaction conditions within a pair of reactors operated inseries. I

It is therefore an object of this invention to produce alkylate productof maximum RON in an alkylation process using two reactors in series.

It is another object of this invention to convert the maximum amount offeedstock in an alkylationprocess using two reactors in series whileproducing alkylate product of maximum RON.

Other aspects, objects and the several advantages of this invention willbe apparent toone skilled in the art from a study of the disclosure andthe appended claims.

SUMMARY OF THE INVENTION 7 Accordingly, by the process of thisinvention, diiso propyl containing alkylate is produced by thealkylation of isobutanean'd ethylene feedstock in the presence of analuminum halide catalyst by a method comprising:

l. feeding isobutane, ethylene and catalyst into a first agitatedreactor wherein the feedstock and catalyst are intimately mixed withhigh agitation for a short period of contact time; 2. feeding theeffluent stream from the first reactor to a second agitated reactorwherein the effluent is terms of the power taken to drive the agitatorina given contactvessel describing the contact vessel in terms of itscontent in volume during the time of agitation contact between theagitator and the material in the vessel. Since, obviously various sizevessels and agita-- tors in combination would yield a varying amount ofagitation of the contents of the vessel, contact energy gives a commondenominator method for, describing the amount of agitation in thevessel.

The contact energy used in agitation of the second reactor vesselcontents should be held Within the range of about 1/10 to 50 percent ofthat of the first reactor. Within this range alkylate degradationis'minimized. Below this range conversion of feedstock is reduced to agenerally commercially unacceptable degree. Above this range it isbelieved that polymerization or further alkylation of the primaryalkylate product reduces the octane number.

A second set of parameters that has been found relevant to maintaining ahigh octane number without significant reduction of conversion offeedstock in an alkylation reaction is the relationship of the contacttime of the reactants within each of the reactor vessels. The contacttime within the second reactor vessel should be held within the range of2 to 6 times the contact time of the more vigorously agitated firstreactor vessel. The greater length of contact time within the lessstrenuously agitated vessel allows for additional conversion offeedstock but does not produce an emulsion thattakes an undue amount oftime to break, or does not break at all, within the settling vessel.

Apreferred embodiment of this invention will now be discussed inconnection with theaccompanying drawing which shows an arrangement ofapparatus-suitable for the practice of the invention. While variousfeatures of the invention will be discussed in connection with thereactor of isobutane and ethylene in the presence of a liquid aluminumchloride-hydrocarbon complex as the catalyst to produce a diisopropylcontaining alkylate, it is to be understood that the invention can beapplied to other reactants and to other catalysts such as I-IF-BFcatalyst, AlBr -type catalyst, and

the like. Referring now to the drawing an isobutane stream is fedthrough line 1 andan. ethylene stream through line 2 to join in line 3to feed into line 4 which carries fresh and makeup-catalyst to feed intoa first reactor 5.'Within reactor 5 an agitator 6, here a stirringagitator, is maintained'at a speed of about 1000 rpmto produce a contactenergy of 20.6 horsepower per 1,000 gallons of reactor vessel content.The liquid is held. within the reactor for approximately 0.7 minuteafter which it is discharged through line 7 The total effluent fromreactor 5 is fed through line 7 into reactor 8. In this'reactorthestirring agitator 9 is maintained at approximately 350 rpm to produce acontact energy of 2.6 horsepower per thousand gallons of reactorcontent. The residence time of material within the second reactor isapproximately 3.1 minutes.

The effluent from reactor 8 is discharged through line 10 into asettling vessel 11 wherein the catalyst which is denser than thealkylate product settles to the bottom of the vessel from which it isfed through line 12 back to the first reactor.

Within the settling vessel the alkylate product and catalyst separatewithin about 60 minutes without problems that could be caused because.the emulsion does not break. Alkylate product and collected feed-Reactor 1, All Runs:

to the reduced agitation in the first reactor. It should be noted thatthe octane rating remains substantially the same for runs 2 and 3.

Reasonable variations and modifications are possible within the scope ofthe foregoing disclosure and the appended claims to this invention theessence of which is that maximum octane rating can be obtained in analkylate product containing diisopropyl without undue sacrifice offeedstock conversion by maintaining high agitation in the first of apair of reactors while reducing the rate of agitation and increasing theresidence time Capacity, gal, 0.24 Temperature, F., 125 m the secondreactor. Pressure, psig., 250-275 w l i Residence Time, minutes 0.7 YReactor 2,Al1R l. A method for producing diisopropyl-containingCapacity, gal, 1.02 5 alkylate by the alkylation of isobutane andethylene Tempcram? 5 feedstock in the presence of an aluminun halidehydro- Pressure, psig, 250-275 Residence Time minutes carbon complexcatalyst while maintaining a balance of Reactant and CatalystConditions: maximum product research octane number (RON) and lsobutaneFeed Pounds/ht q 25 6 m xi eth len feed conversion efficienc said Ethlene Feed. pounds/hr. (liquid) 1.2 a mum y HC pounds/hr. 0.0086 methodCOmPHSmg- Recycle AlClzy p -I 132-0 a. feeding isobutane, ethylene andaluminum halide Temperature of ydrocarbons and Catalyst 20430 into afirst agitated reactor wherein the feedstock and catalyst are intimatelymixed with high agita- USing the reaction conditions'above: (Table onfOltion wherein the contact energy of the agitator is lowing page)maintained in the range of 15 to horsepower per Contact Ener ReactorOutlet Stirrer RPM HP per 1000 ons Alkylate RON Eth lene Conversion RunTemp., "F Reactor 1 Reactor 2 Reactor I Reactor 2 (Clear) eight PercentObserving the table above, comparing runs 1, 2, 4 1,000 gallons ofreactor content during the contact and 5 using the same 1000 rpm to givethe same time between said agitator and said content, contact energy inthe first reactor but using a different b. feeding the effluent streamfrom said first reactor rpm to give different contact energy in thesecond reacto a second agitated reactor wherein the effluent is tor itwill be seen that most of the conversion occurs in 40 subjected toagitation maintained between 0.1 and the first reactor. This is mostreadily apparent in run 5 50 percent of said contact energy in saidfirst reacwith no agitation in the second reactor showing a drop tor andwith the contact time in said second reactor of less than 10 percent inthe ethylene conversion. maintained in the range of 2 to 6 times greaterthan When agitation or stirrer rpm is highest in both reactor saidcontact time in said first reactor, and l and reactor 2, as in run 1,the greatest conversion of c. collecting the diisopropyl-containingalkylate efethylene occurs; This, however, is at the expense of a fluentfrom said second reactor. loss of valuable octane number. Optimumconditions The method of Claim 1 wherem Said Contact are seen withconditions approximating run 2 wherein Said sfictmd reactor 15 q atabout 5 the highest octane product with above the maximum p f of Salt]Contact F g 531d first reactor and conversion f ethylene is Observed,said contact time in said second reactor is about 4.5

C'oncemin runs 2 and 3 where the Contact ener in times greater than saidcontact time in said reactor. the second r actor is held the same whilethe cofit act The method of claim 2 wherein Said Contact time ener inthe first re ctor is than ed t c be Seen that in said first reactor isabout 0.7 minute and said contact gy a an time in said second reactor isabout 3.1 minutes. the reduction of ethylene conversion can beattributed UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OFCORRECTION PATENT NO. 1 3,855,345

DATED I December 17, 197 1 INVENTOR(S) I Thomas Hutson, Jr.; Donald J.Mako \ec It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 51, after "in said" insert first 6 Signed and Sealed thisthirtieth D f March 1976 [SEAL] Attest:

RUTH C. MASON C. MARSHALL DANN AIICSIMR Ojfifl Commissioner oj'PaIenrsum! Trademarks e v n a.

1. A METHOD FOR PRODUCING DIISOPROPYL-CONTAINING ALKYLATE BY THEALKYLATION OF ISOBUTANE AND ETHYLENE FEEDSTOCK IN THE PRESENCE OF ANALUMINUM HALIDE HYDROCARBON COMPLEX CATALYST WHILE MAINTAINING A BALANCEOF MAXIMUM PRODUCT RESEARCH OCTANE NUMBER (RON) AND MAXIMUM ETHYLENEFEED CONVERSION EFFICIENCY SAID METHOD COMPRISING: A. FEEDING ISOBUTANE,ETHYLENE AND ALUMINUM HALIDE INTO A FIRST AGITATED REACTOR WHEREIN THEFEEDSTOCK AND CATALYST ARE INTIMATELY MIXED WITH HIGH AGITATION WHEREINTHE CONTACT ENERGY OF THE AGITATOR IS MAINTAINED IN THE RANGE OF 15 TO30 HORSEPOWER PER 1,000 GALLONS OF REACTOR CONTENT DURING THE CONTACTTIME BETWEEN SAID AGITATOR AND SAID CONTENT, B. FEEDING THE EFFLUENTSTREAM FROM SAID FIRST REACTOR TO A SECOND AGITATED REACTOR WHEREIN THEEFFLUENT IS SUBJECTED TO AGITATION MAINTAINED BETWEEN 0.1 AND 50 PERCENTOF SAID CONTACT ENERGY IN SAID FIRST REACTOR AND WITH THE CONTACT TIMEIN SAID SECOND REACTOR MAINTAINED IN THE RANGE OF 2 TO 6 TIMES GREATERTHAN SAID CONTACT TIME IN SAID FIRST REACTOR, AND C. COLLECTING THEDIISOPROPYL-CONTAINING ALKYLATE EFFLUENT FROM SAID SECOND REACTOR. 2.The method of claim 1 wherein said contact energy in said second reactoris maintained at about 12.5 percent of said contact energy in said firstreactor and said contact time in said second reactor is about 4.5 timesgreater than said contact time in said reactor.
 3. The method of claim 2wherein said contact time in said first reactor is about 0.7 minute andsaid contact time in said second reactor is about 3.1 minutes.